Protoceratopsidae was named by Granger and Gregory (1923). Its type is Protoceratops. It was considered paraphyletic by Dodson (1997) and monophyletic by Sereno (2000).

It was synonymized subjectively with Leptoceratopsinae by Huene (1934) and Huene (1934); it was corrected as Protoceratopidae by Olshevsky and Ford (1994), Tereshchenko and Alifanov (2003) and Tereshchenko (2007).

It was assigned to Orthopoda by Bohlin (1953); to Ponderopoda by Huene (1948) and Huene (1959); to Ceratopsoidea by Zhao (1983), Norman (1984) and Cooper (1985); to Neoceratopia by Olshevsky and Ford (1994); to Ceratopsia by Gregory and Mook (1925), Lull (1933), Roxo (1937), Brown and Schlaikjer (1942), Kuhn (1946), Huene (1950), Romer (1956), Parsch (1963), Tatarinov (1964), Kuhn (1964), Kuhn (1966), Romer (1966), Charig (1967), Swinton (1970), Thulborn (1971), Maryanska and Osmólska (1975), Rozhdestvensky (1977), Ostrom (1980), McIntosh (1981), McGinnis (1982), Sues and Galton (1982), Russell (1984), Maryanska and Osmólska (1985), Ostrom and Wellnhofer (1986), Bakker (1986), Carroll (1988) and Nessov (1995); to Neoceratopsia by Dodson and Currie (1990), Dodson (1990), Dodson (1997), Ryan and Currie (1998), Chinnery and Weishampel (1998), Lambert et al. (2001), Tereshchenko and Alifanov (2003), Chinnery (2004) and Ott (2007); to Protoceratopoidea by Tereshchenko (2007); and to Coronosauria by Sereno (1997), Sereno (1998), Sereno (1999), Sereno (2000), Makovicky (2001), You and Dodson (2003), Butler et al. (2008) and Morschhauser et al. (2019).